Not had the pleasure yet, but our old A6 was quattro and I ran Dunlop Winter Sport tyres on it. And did every year for about 5 years. Before that we had a BMW 530d and I ran winters on that too and also on our convertible Mini.
Just before Christmas I swapped them out the day before we had a massive dump of snow. I went to the supermarket in the morning with absolute ease, but all around me was carnage. The only problem with that car was that it was so long and low, that it would ground out and get stuck way before you lost traction.
There were cars abandoned left, right and centre and at one point, I saw a big 'proper' 4x4 boot it out of a side road and do a full 360 spin into the kerb opposite.
I'd much rather go out in our 2WD mini and winter tyres on snow rather than in a 4x4 and summer tyres.
Now I just need to source some winter wheels and tyres for the Q5.